MOSCOW - The IAAF wants two Russian race walkers to be stripped of medals from the 2012 London Olympics because of doping, the Russian anti-doping agency said Thursday.

The IAAF said Wednesday it has lodged an appeal with the Court of Arbitration for Sport against the "selective" doping bans handed to six Russian athletes earlier this year, arguing that the Russian agency decision wrongly let some results stand.

The agency, Rusada, confirmed in a statement Thursday that a key focus of the appeal is that "the IAAF did not agree with our decision to leave in force" results for walkers Sergei Kirdyapkin and Olga Kaniskina at the London Olympics.

Kirdyapkin won gold in the men's 50-kilometre event, while Kaniskina was the silver medallist in the women's 20-kilometre race.

In its dispute with the IAAF, Rusada has the support of Russia's influential Sports Ministry, deputy minister Yuri Nagornykh told Russia's Tass news agency.

"Our lawyers consider that what Rusada did with regards to this issue was right," he said. "Specialists will study this situation and the issue will be decided in the legal field. In order to say something definite, it's firstly necessary to wait for the relevant documentation from the IAAF and to study them attentively."

Apart from Kirdyapkin and Kaniskina, the other athletes involved are walkers Sergei Bakulin, Vladimir Kanaykin and Valery Borchin, as well as 3,000-meter steeplechase runner Yulia Zaripova. If the bans are extended, Zaripova and Bakulin risk losing gold medals from the 2011 world championships.

Kaniskina could also lose her gold medal from the 2010 European championships.